Xerographic apparatus



" J. G. HANSEN ETAL 3,196,766

XEROGRAPHIC APPARATUS 14 Sheets-Sheet 1 i126. Sept. 3, 1963 INVENTORSJOHN G. HANSEN JACK R. OAGLEY A T TOR/ 1E)" July 27, 1965 J. G. HANSENETAL 3,

XEROGRAPHIC APPARATUS Filed Sept. 5, 1963 14 Sheets-Sheet 2 INVENTOR.JOHN G. HANSEN JACK ROAGLEY BY Arrow/5y July 27, 1965 J. G. HANSEN ETAL3,196,766

XEROGRAPHIC APPARATUS Filed Sept. 3, 1965 14 Sheets-Sheet 3 JOHN G.HANSEN BY JACK R. OAGLEY A TTORNE Y 14 Sheets-Sheet 4 J. G. HANSEN ETALXEROGRAPHIC APPARATUS July 27, 1965 Filed Sept. 3, 1963 INVENTOR. JOHNG. HANSEN JACK R. OAGLEY BY ATTORNEY July 1955 J. G. HANSEN ETAL 3,

' XEROGRAPHIC APPARATUS Filed Sept. 5, 1963 14 Sheets-Sheet 5 INVENTOR.JOHN G. HANSEN BY JACK R. OAGLEY A T TORNE Y July 27, 1965 J. G. HANSENETAL XEROGRAPHIC APPARATUS 14 SheetsSheet 6 Filed Sept. 5, 1963INVENTOR. JOHN G. HANSEN BY JACK R. OAGLEY ATTORNEY J y 1965 J. G.HANSEN ETAL 3,196,766

XERUGRAPHIC APPARATUS Filed Sept. 5, 1963 14 Sheets-Shea; 7

wmw kw Rm NR INVENTOR. JOHN G. HANSEN BY JACK R. OAGLEY 4, M

A r romvsv July 27, 1965 J. G.- HANSEN- ETAL XEROGRAPHIC APPARATUS- 14Sheets-Sh eet 8 Filed Sept. 3, 1963 INVENTOR. JOHN G. HANSEN B JACK R.OAGLEY A T TOBNE Y July 2 1 J. G. HANSEN ETAL 3,1 6,

XEROGRAPHIC APPARATUS Filed Sept. 3, 1963 14 Sheets-Sheet 9 INVENTOR.JOHN G. HANSEN JACK R. OAGLEY A T TORNE Y July 27, 1965 Filed Sept. 3,1963 J. G. HANSEN ETAL XEROGRAPHIC APPARATUS 14 Sheets-Sheet 10 FIG. 11

INVENTOR. JOHN G. HANSEN JACK ROAGLEY A T TORNE Y July 27, 1965 J. G.HANSEN ETAL XEROGRAPHIC APPARATUS 14 Sheets-Sheet 11 Filed Sept. 3, 1963INVENTOR. JOHN G. HANSEN BY JACK R. QAGLEY ATTORNEV July 27, 1965 FiledSept. 3, 1963 J. G. HANSEN ETAL XEROGRAPHIC APPARATUS 14 Sheets-Sheetvl2 FIG. 1.3

INVENTOR.

JOHN G. HANSEN BY JACK R. OAGLEY wyw ATTORNEY y 1965 J. G. HANSEN ETAL3,196,766

XEROGRAPHIC APPARATUS Filed Sept. 3, 1963 I 14 Sheets-Sheet 13 672 I k662 I INVENTOR. JOHN G. HANSEN B JACK R. OAGLEY A TTORNEV July 1965 .1.G. HANSEN ETAL 3,

XEROGRAPHIC APPARATUS Filed Sept. s, 1963 14 Sheets-Sheet l4 PS-lINVENTOR.

- JOHN G. HANSEN roe JACK ROACLEY BY F1615 M- ?/4.4,,

A T TORNE' Y United States Patent 0 3,196,766 XERQGRAPHIC APPARATUS JohnG. Hansen, Pittsford, and Jack R. (lagley, Rochester, N.Y., assignors toXerox Corporation, Rochester, N.Y., a corporation of New York FiledSept. 3, 1963, Ser. No. 305,995 6 Claims. (Cl. 95-13) This inventionrelates to facsimile recorders and, in particular, to xerographicfacsimile recorders.

More specifically, this invention relates to a facsimile recorderwherein an electrical picture signal, produced from a document at aremote location, is received by the facsimile recorder throughtransmitting facilities, such as common carrier channels, coaxial cablesor microwave relay equipment, and is translated into a facsimile of theoriginal document by applying the signal to a cathode ray tube in theoptical system of a xerographic reproducing machine.

The increasing need for facsimile reproductions at remote locations hasinspired a variety of different approaches to the inherent problems oftranslating electrical picture signals into a facsimile of the originaldocument. Although there are many approaches to the problems which areoperable and there are a number of commercially available systems, eachhas inherent limitations when considered from the standpoint of highspeed, high resolution reproduction. Many of the recording methods areslow and relatively ineflicient. The quality of the image reproduced isusually inferior to that of the original document. Most reproductionsystems require specially treated paper and usually require anelectrical arcing device or electrical current flow, to mark paper orcause chemical changes to develop photographic images on paper. Thesemethods are either very slow or produce poor quality images.

In the process of xerography, as disclosed in either Carlson Patent2,297,691, issued October 6, 1942, or in Carlson Patent 2,357,809,issued September 12, 1944, a xerographic plate comprising a layer ofphotoconductive insulating material on a conductive backing is given auniform electric charge over its surface and is then exposed to thesubject matter to be reproduced, usually by conventional projectiontechniques. This exposure discharges the plate areas in accordance withthe radiation intensity which reaches them and thereby creates anelectrostatic latent image on or in the plate coating. The developmentof the image is effected with developer material or developers whichcomprise, in general, a mixture of a suitable pigmented or dyedelectroscopic powder, hereinafter referred to as a toner, and a granuleof carrier material, which functions to carry and to generate atriboelectric charge on the toner. More exactly, the function of thegranule material is to provide the mechanical control to the powder, orto carry the powder to an image surface and, simultaneously, to providealmost complete homogenity of charged polarity. In the development ofthe image, the toner powder is brought into contact with the plate andis held thereon electrostatically in a pattern corresponding to theelectrostatic latent image. Thereafter, the developed xerographic imageis usually transferred to a support or transfer material to which it maybe fixed by any suitable means.

The process of xerography as disclosed in the abovementioned Carlsonpatents provides a solution to the inherent problems of facsimilerecording. Rather than exposing the photoconductive surface to a lightimage of the copy being reproduced, to discharge the uniformelectrostatic charge on the photoconductive surface, it is possible todischarge the uniform electrostatic charge in incremental areas byexposing the photoconductive surface Patented July 27, 1965 to the beamof a cathode ray tube. By controlling the on-oif orientation of thecathode ray tube in response to an electric signal received inconformity with the original image on the document being reproduced, anelectrostatic image may be generated on the photoconductive surface. Atransmitting and receiving system of this type is described in thecopending application Serial No. 240,097, filed November 26, 1962, inthe names of Charles Huber, John Wheeler, and Elliot Woodhull.

It is the primary object of this invention to improve facsimilerecording apparatus to reproduce images of an original document byxerographic means;

It is also an object of this invention to improve xerographic apparatusto reproduce documents in accordance with electrical signals receivedfrom a remote location;

It is also an object of this invention to improve facsimile recordingapparatus to control the recorder in response to signals received from aremote location and to indicate to a remote location that the recorderis in condition to record electrical signals received.

For a better understanding of the invention, as well as other objectsand further features thereof, reference is had to the following detaileddescription of the invention to be read in connection with theaccompanying drawings wherein:

FIG. 1 is a right-hand perspective view of the apparatus of theinvention;

FIG. 2 is a schematic illustration of the apparatus of the invention;

FIG. 3 is a front view of the apparatus taken with the cabinet coversremoved and with the paper cutter removed to show the internal structureof the apparatus;

FIG. 4 is a sectional view of the xerographic apparatus taken alonglines 44 of FIG. 3;

FIG. 5 is a sectional view of the optic system taken along lines 55 ofFIG. 3 with portions broken away to show internal structure;

FIG. 6 is a left-hand perspective view of the drive system of theapparatus along with the shafts and rolls being driven with parts andsections and removed from the rest of the apparatus;

FIG. 7 is a perspective view of the web cleaner and of the fuserapparatus;

FIG. 8 is an enlarged view of the clutch mechanism for the take-up rollof the web cleaner apparatus;

FIG. 9 is a left-hand sectional view of the web cleaner and the fuserapparatus taken along lines 9-9 of FIGURE 3;

FIG. 10 is a sectional view of the web cleaning roll drive mechanism ofthe web cleaner apparatus;

FIG. 11 is a front sectional view of the fuser apparatus taken alonglines 11-11 of FIG. 9;

FIG. 12 is a front sectional view of the paper cutter apparatus takenalong lines 1212 of FIG. 4;

FIG. 13 is a left-hand section view of the paper cutter apparatus takenalong lines 13-13 of FIG. 12;

FIG. 14 is a left-hand view of the paper cutter apparatus shown in FIG.12; and

FIG. 15 is a schematic electrical circuit wiring diagram of theapparatus.

General FIG. 1 shows the facsimile recorder 2 with side covers 4, afront panel 6, and a display panel 8. The facsimile recorder consistsgenerally of a cathode ray tube It) which emits a light spot through alens assembly .12 onto a mirror 14 from which it is reflected to asecond mirror 16 onto the surface of a xerographic drum 18. Thexerographic drum is suitably joumaled in a side frame and rotates in thedirection indicated by the arrow to cause the drum surface sequentiallyto pass a plurality of xerographic processing stations.

For purposes of the present disclosure, the several xerographicprocessing stations in the path of movement of the drum surface may bedescribed functionally, as follows:

A charging station, at which a uniform electrostatic charge is depositedon the photoconductive layer of the xerographic drum;

An exposure station, at which the drum surface is exposed to thesweeping light ray of the cathode ray tube to dissipate theelectrostatic charge on the drum surface in the areas exposed to lightand to retain the charge in areas that are not exposed to light, therebyforming a latent electrostatic image in conformity with electricalsignals controlling the cathode ray tube;

A developing station, at which a xerographic developing material,including toner particles having an electrostatic charge opposite tothat of the electrostatic latent image, is cascaded over the drumsurface, whereby the toner particles adhere to the electrostatic latentimage to form a xerographic powder image in the configuration of theelectrostatic latent image produced by the light spot from the cathoderay tube;

A transfer station, at which the xerographic powder image iselectrostatically transferred from the drum surface to a transfermaterial or a support surface; and

A drum cleaning station, at which the drum surface is first charged withan electrostatic charge and then brushed or wiped to remove residualtoner particles 'remaining thereon after image transfer, and at whichthe .drum surface is exposed to a relatively bright light source toeffect substantially complete discharge of any residual electrostaticcharge remaining thereon.

The charging station is preferably located, as indicated by referencecharacter A in the schematic illustration of the apparatus. In general,a charging apparatus or corona charging device 2% includes a coronadischarge array of one or more discharge electrodes that extendtransversely across the drum and are energized from a high potentialsource and are substantially enclosed within a shielding member. 7

Next subsequent thereto in the path of movement of the xerographic drumis an exposure station E. This exposure station consists of the mirror16 pivotally mounted at an angle to deflect light rays onto thexerographic drum through a slotted light shield 22. The light shield isadapted to protect the xerographic plate from extraneous light. Theslotted aperture 24 in the light shield ex tends transversely to thepath of movement of the light receiving surface of the xerographic drumto permit the light rays from the cathode ray tube 1% to be directedagainst a transverse incremental area of the light receiving surface asit passes under the shield 22.

Adjacent to the exposure station is a developing station C in whichthere is positioned a developer apparatus 26 including a developerhousing, shown in FIG. 4, having alower or sump portion for accumulatingdeveloper material 28. Mounted within the developer housing is a drivenbucket type conveyor 3% used to carry the developer material to theupper portion of the developer housing from where it is cascaded over ahopper chute 32 onto the drum surface.

As the developer material cascades over the drum, toner particles of thedeveloper material adhere electrostatically to the previously formedelectrostatic latent image areas on the drum to form a visiblexerographic powder image. The developer material containing theremaining developer powder falls off the peripheral surface of the druminto the bottom of the developer housing. Toner particles consumedduring the developing operation are replenished by a toner dispenser 34,of the type disclosed in copending application Serial No. 776,976, filedNovember 28, 1958, in the name of Robert A. Hunt, mounted within thedeveloper housing.

Positioned next adjacent to the developer station is the image transferstation 1). At the image transfer station a support material 36, hereinshown as a web of paper, is fed from a supply roll 38 around a pair ofidler rollers 4d and 42 to a second pair of rollers 44 and 46 adjacentto the xerographic drum so that the web of paper is brought into contactwith the drum surface. The web of paper then continues through axerographic fuser, indicated generally as 48, around a roller 50,through a pair of driving pinch rollers 52 to either a tear bar 54 oraround a pair of guide rollers 56 and 58 at feed-out station 64 to atake-up roll 69. Alternatively, the web may pass through a paper cutter,generally indicated as 62, at feed-out station 64. and drop asout-sheets in a bin 66. The web path for paper cutter and tear bar areshown in dotted lines in FIG. 2.

The transfer of the xerographic powder image from the drum surface tothe support material is effected by means of a corona transfer device 68which is located at, or immediately after, the point of contact betweenthe support material and the rotating xerographic drum. The coronatransfer device 68 is substantially similar to the corona dischargedevice that is employed at the charging station in that it also includesan array of one or more corona discharge electrodes that are energizedfrom a suitable high potential source and extend transversely across thedrum surface and are substantially enclosed with a shielding member. Inoperation, the electrostatic field created by the corona transfer deviceis efiective to tack the transfer material electrostatically to the drumsurface and, simultaneously with the tacking action, the electrostaticfield is effective to attract the toner particles comprising thexerographic powder images from the drum surface and cause them to adhereelectrostatical'ly to the surface of the support material.

As the web of material moves forward away from the xerographic drum,there exists on the surface of the support material a powder image sothat as the web: passes between the rollers '70 and 72 of the fuser 48,the powder image is fused onto the surface of the support material andis permanently fixed thereto.

The next and final station in the device is a drum cleaning station Ewhereat any powder remaining on the xerographic drum after the transferstep is removed and whereat the xerographic drum is flooded with lightto cause dissipation of any residual electric charging remainingthereon.

To aid in the removal of any residual powder remaining on the drumsurface, there is provided a corona precleaning device 74 that issubstantially similar to the corona discharge device that is employed atcharging station A. Removal of residual powder from the xerographic drumis effected by means of a web cleaning device 76 adapted to continuouslyfeed a clean fibrous web of material into wiping contact with thexerographic drum. As shown, the web material 78 is taken from a supplyroll 80 and transported around a cleaning or pressure roll 82,preferably made of rubber, onto a takeup or rewind roll Any residualelectrical charge remaining on the xerographic drum is dissipated bylight from a fluorescent lamp 36 mounted in a suitable bracket above thexerographic drum, a suitable starter and ballast being provided forenergizing the fluroescent lamp.

Suitable drive means, described below, drive the xerographic drum, thedrive rolls for the web of support material, the fuser, and a webcleaner mechanism, the latter being driven at a speed, or speeds,whereby relative movement between the xerographic drum and the webmaterial is effected. Suitable drive means are also provided foreffecting operation of the conveyor mechanism and the toner dispenser ofthe developing apparatus assembly.

As seen in FIG. '3, there is provided a frame for supporting thecomponents of the apparatus formed by a left-hand plate 88, anintermediate plate 9i), and a righthand plate 92 connected together andmaintained rigidly in spaced relation to each other by suitable tierods.

The Xerographic drum 18 having a layer of photoconductive insulatingmaterial on a conductive backing, is mounted on a horizontal drivenshaft 94 that rotates in bearings mounted in plates 93 and 92. The drumis mounted on shaft 94 in cantilever fashion and the free end isthreaded to receive a nut to retain the drum on the shaft.

Optical system Electrical signals, received from a remote source, areused to control the exposure of the Xerographic drum to light. Thus, theelectrical signal is basically used to construct an electrostatic latentimage on the drum surface. The optical system must, therefore, use asource of light responsive to electrical signals, herein a cathode raytube. The cathode ray tube is mounted inside the machine with theappropriate electronic apparatus, not shown, required to convert theelectrical signal into a light say. The type of electronic apparatusrequired for the operation of a cathode ray tube is well known in theart and does not constitute part of the present invention. However, anexample of the type of system that may be used is disclosed in theabove-mentioned copending application of Charles L. Huber et al., SerialNo. 240,097, filed November 26, 1962.

Referring to FIG. 5, an optical casting 1563 supports the entire opticalassembly. The cathode ray tube 1d is mounted within a container 132which is supported on support plate 134 by bracket 135 and support ring138 at one end. and at the other end by block 140 and connector 1412.The support plate 134 is adjustably mounted on the optical casting 130so that the cathode ray tube may be raised or lowered to change therelative position of the light spot on the tube face. The light spotscans a straight line across the face of the tube and, after extendedusage, produces burn-out of the phosphor on the face of the who alongthe scan line. In such event, the vertical deflection of the spot may beadjusted to scan a new line on the tube face and the tube may bephysically adjusted so that the new scan line is in the same relativeposition to the rest of the optic system as the original scan line.

For purposes of physical adjustment of the cathode ray tube, the supportplate 134 is mounted upon a set of shims 144- resting on adjustmentblocks 1% which are supported upon a pair of bosses 148 on the opticalcasting 13th, as seen in FIGS. 3 and 5. The support plate is fastenedthrough the shims 144 and the adjusting blocks 146 to the opticalcasting 13% by means of screws f). There is an adjustment assembly asjust described in each of the four corners of the support plate 134. Theadjustment blocks contain stepped thicknesses such that as the blocksare rotated a different level of thick ness is presented to the boss 148 varying the height of the support plate and the cathode ray tubeabove the optical casting 130. This produces a fine adjustment of thecathode ray tube. The shims 144- may either be added or removed toprovide further adjustments beyond the range of the steps in theadjustment blocks.

At the rear of the cathode ray tube, the front of the recorder, there islocated a lateral or horizontal adjustment assembly for the cathode raytube. An adjustment block 152 is secured to the optical casting 131) bybolt 154 and contains set screw 156 which bears against the supportblock 140 and the end of the support plate. Adjustment of the set screw156 will produce horizontal movement of the support plate 134.

A lens system support bracket 158 is secured to the optical casting 130and supports the lens system 12 and the mirror 14. The lens system 12consists of a lens 16!) mounted in a lens barrel 162 which is adjustableby rotation of outer barrel 164. The mirror 14 is a front surface mirrorand is held in a bracket 166 by leaf spring 168. The bracket 166 ispivotally secured to the frame member 1555 by conventional ball andsocket joints on each end, not shown, and has tightening means to lockthe ball and socket joints and prevent movement of the mirror.

A second mirror 16 is mounted and supported above the Xerographic drumat the light shield 22 by the same type of bracket and leaf springarrangement described for the mirror 14. The light spot from the cathoderay tube passes through the lens 16% onto the surface of the mirror 14-where it is reflected downward onto the surface of the mirror 16 fromwhich point it is reflected through the light shield 22 onto the surfaceof the Xerographic drum. The light spot is moved across the surface ofthe face of the cathode ray tube and, ultimately, in lines across thesurface of the Xerographic drum. That is, the light spot scans thesurface of the Xerographic drum in a series of lines parallel to theaxis of the drum. The on-oif orientation of the light spot is controlledby the incoming electrical signal and effects discharge of anelectrostatic charge on the drum surface in accordance with theelectrical signals received.

Drum cleaning assembly After transfer of a powder image from the drumsurface to the web or support material, it is necessary to clean theresidual powder from the drum before making a new image on the drum. Toremove the residual powder after transfer, there is provided a drumcleaning assembly. Also to dissipate any residual electric chargeremaining on the drum a light source is used to flood the portions ofthe xerographic drum with light as it passes through the cleaningstation.

Referring to FIGS. 7 through 10, the drum cleaning assembly is shown ascontaining a Web cleaner 76, which includes a supply roll 80, preferablyformed as a disposable cardboard cylinder, carried on a supply rollshaft 202 journaled in frame plates and 92. The supply roll is held onthe supply roll shaft by means of a spring snap retainer 294 secured tothe free end of the shaft, the slotted end of the supply roll engagingthe pin 206 in the shaft. As the web of material 78 is pulled from thesupply roll, the shaft 202 must be rotated, thereby imparting a slightresistance to the unwinding of the Web material from the supply roll.

The web material '78 is brought into cleaning contact with the drumsurface by cleaning or pressure roll 82, preferably made of rubber,bonded to a support cylinder 2938. cylinder 2% is supported at oppositeends by stub shafts 216 and 212 journaled in yokes 214 and 216, respectively, fastened in spaced apart relation to each other on a torque tube218. The cleaning or pressure roll is driven by pin 420 on the end ofstub shaft 212 engaging the notched end of cylinder 208, a driven gear222 being fixed to the opposite end of the stub shaft.

The torque tube 218 is rotatably supported on yoke shaft 224, which isfastened at one end by set screw 426 in support 428, secured to frameplate 90. At its output end, the torque tube is journaled on tapered pin430 in support arm 432 pivotally mounted to frame plate 88. Support arm432 is normally biased into position to support the output end of torquetube 218 by means of a coiled spring, not shown.

The torque tube 218 supports the yokes 214 and 216 Which, in turn, carrythe cleaning or pressure roll 82. Thus, the pressure roll 82 may berotated on the yokes 214 and 216 about the center of the torque tube 218from a cleaning position, as shown in FIG. 7, with the peripheralsurface of the roller against the outer surface of the Xerographic drumwith the web of material sandwiched therebetween to a second position inwhich the cleaning roll is in an inoperative position away from thesurface of the Xerographic drum. The purpose for moving the pressureroll away from the surface of the Xerographic drum is twofold. First, itis necessary that the web material be placed between the pressure rolland the drum surface so that when a new web is placed upon the supplyroll the pressure roll may be swung away from the drum to allow the webto be placed between the pressure roll and the drum surface and attachedto the takeup roll. Secondly, the drum has a continuous layer ofphotoconductive material on the surface thereof and when the machine isnot in operation, if the pressure roll is pressing against the drum atone spot, the photoconductive surface would be damaged in that areaproducing irregularities in the copies produced in that area. Therefore,when the machine is not running, the compression roll is swung away fromthe drum surface by means described below.

The cleaning roll is biased into pressure contact with the peripheralsurface of the xerographic drum by means of compression spring 234. Thecompression spring encircles a spring guide 236 which serves as a linkextending radially from a shaft 233 journaled in frame plates hi) and 2to the yoke 216.

One end portion of the compression spring engages the shoulder on thelower end of spring guide 235 and the opposite end portion of thecompression spring engages the shaft 238. The guide 236 is movablymounted at one end in a suitable opening in shaft 238 and its movementin one direction is limited by washer head screw Z40, adjustablythreaded into the end of the guide. With this arrangement, the axis ofthe cleaning roll is biased by the compression spring 234 to a fixedposition relative to the peripheral surface of the xerographic drum asdetermined by the washer head screw. The normal forces supplied by thecleaning roll against the xerographic drum surface with the web materialsandwiched therebetween is dependent upon the spring rate or deflectionof the material of the cleaning roller and the poistion of the axis ofthe cleaning roller relative to the Xerographic drum as determined bythe washer head screw 2% acting as a stop or guide 23% It has been foundthat effective cleaning is obtained when the normal forces of thepressure or cleaning roll against the Xerographic drum with the webmateiral therebetween is in the range of ten to thirty pounds,preferably twenty pounds.

The guide 256 and the compression spring act as an overriding linkagepermitting the compression spring to either bias the cleaning rollagainst the peripheral surface of the drum, that is, to bias the axis ofthe cleaning roll to a fixed position when in its operative position, orto bias the cleaning roll away from the drum to its inoperativeposition.

The cleaning roll 82 is rotated by gear 222 on stub shaft 212, engagingthe compound gear 242 journaled on yoke shaft 224. Axial alignment ofthis gear is maintained by spacer 2%. Compound gear 242, in turn, isdriven by compound gear 246 on the drum shaft 24?; through pinion gear250 in compound gear 252. Pinion gear 25% and compound gear 252 aremounted on stub shafts 254 journaled in front support plate 255 and rearsupport plate 258.

A switch bracket 260, front support plate 256 and rear support plate 258are mounted on studs 26?, secured to support 228. The switch bracket ismaintained in spaced relation to the front support plate by spacers 264and the front support plate is held in spaced relation to the rearsupport plate by spacers 266.

The take-up roll 84, preferably formed as a disposabl cardboard cylindersimilar to supply roll 89, is positioned on take-up shaft 268 by aspring snap retainer 2% secured to the free end of the shaft, theslotted end of the take-up roll engaging the pin 276]) in shaft 2x33.

The take-up shaft 263, iournaled in the flame plates 9%? and 92, isdriven by compound gear 252 and driving gear 272 journaled on the shaftthrough a slip clutch arrangement in which the end face of gear adjacentthe torque nut 274 serves as one clutch element coasting with the secondclutch element or torque nut 2,7 adjustably positioned on the shaft bytorque screw 2'76 and set screw 278. This assembly is secured againstrotation relative 8 to the take-up shaft by en agement of a radial pin28% carried by the shaft and in a slot provided in the torque screw.

In order to provide means for applying the required pressure to thecoacting clutch elements, gear 272 and torque nut 2'74, and annularspring 232 encircles the shaft between the gear 272 and thrust washers234 and 286 retained by snap ring 283 positioned in a suitable grooveformed on the take-up shaft.

The torque nut 274i is adjusted on the torque screw so that the forcesupplied by the annular spring 2% is sufficient to permit the gear 2'72to drive the take-up shaft through the torque nut to rewind the webmaterial onto the take-up roll as it is advanced by the cleaning roll incooperation with the drum surface, while still permitting the clutchelements to slip relative to each other whereby the desired range oftension on the web material is maintained. In this manner, the webmaterial is advanced only by the .ion of the cleaning roll and not bythe takeup roll.

With this arrangement, the web material is advanced by the cleaning rollat a speed relative to the lineal speed of the drum surface whereby theweb material will wipe the residual powder that may remain on thexerographic plate after the transfer process.

When the machine is not in operation, the pressure roll 82 is withdrawnfrom contact with the drum 1155 by pivoting the yokes 21 i and 216 abouttorque tube 218 to prevent damage to the drum surface by the pressurethat would be exerted on one spot of the drum surface during shutdownperiods. The mechanism to effect move ment of the pressure roll awayfrom the drum surface works in conjunction with the operation of thefuser 43 and is described below thereunder.

F user As previously described, a powder image is developed on theXerographic drum and transferred to the web of support material 36,usually paper, and must be fused or bonded thereto to produce permanencyof the reproduced. copy. The toner or powder used is usually a pigmentedthermoplastic resin, a number of which are manufactured and marketed byXerox Corporation of Rochester, New York, and are specificallycompounded producing dense images of high resolution and to havecharacteristics to permit convenient storage and handling. Theindividual particles of resin (toner) soften and coalesce when heated sothey become sticl; I or tackitied and readily adhere to the surface ofthe transfer material.

The term tackified and the several variant forms thereof used throughoutthis specification are employed to define the cor "'ion of the powderparticles of the xerographic powder image when heated in a manner suchthat the individual particles soften and coalesce and in which statethey become sticky and readily adhere to other surface Although thiscondition necessarily requires a flowing together or" the particles toeifect a thorough fusion thereof, it is to be understood that the extentof such flowing is not sufficient to extend beyond the boundary of thepattern in which the particles are formed.

The support material used is usually paper, as shown for the preferredembodiment disclosed herein by web 36, and is capable of having theresinous powder bonded thereto by heat fusing. in order to fuse resinouspowder images formed by the powder resins now commonly used, it isnecessary to heat the powder and the paper to which it is to be fused toa relatively high temperature, such as approximately 256 F. to 270 F. Itis undesirable, however, to raise the temperature of the papersubstantially higher than 375 F. because of the tendency of the paper todiscolor at such elevated temperatures.

The fuser disclosed herein is a direct contact fusing device in whichthe oner fused by forwarding the web of paper bearing the toner imagebetween the two rolls 70 and 72, the roll 73 contacting the image beingprovided with a thin coating of a Du Pont Corporation product composedof tetrafiuoroethylene resin sold under the trademark Teflon, and asilicon oil film to prevent toner from adhering to the roll. Both theTeflon and the silicon oil have such phyical characteristics that theyare highly repellant to sticky or tacky substances. The Teflon is achemically inert, non-porous and non-absorbent, relatively hard andgenerally form-retaining waxlike synthetic resin which is slightlyelastic under low stress and which is capable of cold-flowing undergreater stress and which is capable of sliding over a surface.

The silicon oil is applied to the surface of roller '70 in a thin filmto further prevent the toner from adhering to the surface of the roller.As seen in PEG. 9, a felt pad 302 extends around a portion of thesurface of roller 70 which does not come in contact with the paper andextends upward to form a loop above the roller which acts as a reservoirfor the silicon oil. The felt pad 302 is held in contact with thesurface of the roller 76 by means of a pair of thin plates 3% shapedwith an internal configuration to fit the outer surface of the rollerand to have a portion extending above the roller to be clamped togetherby means of a screw 3% extending through the extended portion of theplates 304 and nut 3%. The spring 31%, around the shaft of screw 3%,presses against the head of screw 3% and one of the plates 394 so thatthe pressure of the plates 3% on the felt pad 3% remains fairly constantand the pressure of the felt pad against the surface of the roller 70also remains constant despite variation in the thickness of the felt pador in the amount of oil remaining in the felt pad after usage.

The felt pad 302 is initially dipped and soaked in silicon oil so thatas the roller 70 rotates inside the felt pad a thin film of the siliconoil is deposited on the surface of the roller. As the oil is depletedfrom the felt pad in the area around the roller, additional oil willseep down from the loop or reservoir above the roller. After extendedoperation of the apparatus, additional silicon oil may be applied to theloop of the felt pad 392 or the entire pad may be removed and resoakedin silicon oil, or a new pad inserted.

The heated roller 70 consists of a cylinder 312 inside the Teflon cover.The cylinder is closed at opposite ends by fuser roll caps 314, as seenin FIG. 11, which are secured to the cylinder as by a press fit. Aspindle portion of the fuser roll caps are journaled for rotation inbearings 316 mounted in plates 318 and 320. Insulated caps 340 areprovided to support a quartz tube 324 which contains a suitableresistance heating element R1. The resistance element R1 is connected bysuitable conductors to a source of power, such as a commercial 120 volt,60 cycle, alternating current outlet by connections 326. Two thermostats(not shown) are positioned in close proximity to the outer surface ofthe heated roller 73. One thermostat controls the power to theresistance element R1 and, thus, the temperature of the roller, and thesecond thermostat is responsive to a minimum temperature of the rollerand is included in the electrical cir cuitry to produce a signalindicating that the fuser is up to its minimum temperature and a signalmay be sent to start the reproducing processes. This latter thermostatis described below under the operation of the machine. In series withthe second thermostat there is included a fusible link, as a safetyelement, which will open the circuit in case of extreme over-heating.

The left end of the heated roller '70, as seen in FIG. 11, is heldsecure in plate 318 by means of an annular bearing cap 323 and an innerannular bearing retainer 330, which are held together against plate 318by means of screw 332. The cap 328 and the retainer 330 hold the outerrace 334 of the bearing 316 in a fixed position. The one end of theinner race 335 of the bearing 316 abuts against a shoulder of the rollercap 314 and the outer edge of the race 336 is held in position by a snapring 338. At the opposite, or right-hand end of the roller '70, there isalso an outer annular bearing cap 328, which is fastened to side plate320, but which does not contact the outer race 334, thus allowing forexpansion of the heated roller and lateral movement of the bearing 316.At each end of the roller there is an insulated cap 340 fastened to thebearing caps 328 by screws 342 and supporting the electrical connectionsto the resistance element R1 with suit-able connections to a source ofpower at 326.

The pressure roller '72 consists of a metal inner roller in an outercovering of suitable high temperature rubber 346 adapted to be pressedagainst the heated roller 79 and to force the paper web 35 into intimatesurface contact with the roller 76. The pressure between the rollers '70and '72 is such as to provide approximately one-quarter inch of surfacecontact between the two rollers over the length of the rollers. In theembodiment shown, the pressure between the two rollers is approximatelyfortyfive pounds and is produced in a manner described below.

The pressure roller 72 is journaled in a pair of gibs 359 which ride inslots 352 in the side plates 318 and 320. The gibs 35% contain ballbearings 348 which support the shaft 344 of the pressure roller '72 forrotation therein. The outer race of ball bearing 348 on the lefthandside of shaft 344 is held' secure by an inner annular lip 35% on gib356, and the inner race abuts a shoulder on the shaft 344. The outeredges of the races of bearing 348 are held in position by bearing cap356 secured to gib 350 by screws 358. The bearing cap 356 extends beyondthe edges of the gib 356, as seen in FIG. 9, to provide an overlap onplate 318 and provide a sliding surface to retain the gib 350 in theslot 352 of plate 318. The right-hand support for shaft 344 is similarto the lefthand support except that allowance has been made for lateralmovement of the roller due to heat expansion. The bearing 348 issupported by the gib 359 in slot 352 of the plate 320. However, there isno inner annular lip on the gib used on the right-hand support and theretaining cap 360 is secured to the gib by screws 362 but does notextend over any portion of the bearing 348 and thus does not restrictmovement of the bearing 348 in a lateral direction. The cap 3-30 doesextend outward over the plate 320 to provide a sliding surface whichalso retains the gib 359 in the plate 320.

The gibs 350 are movable in a vertical direction in slot 352 to bringthe pressure roller 72 into and out of contact with the pressure roller70 so that when the fuser is not in operation the pressure between thetwo rollers may be relieved and the surface of the rollers will not bepermanently deformed. The actuating mechanism to move the pressureroller into and out of contact with the heated roller is describedbelow.

Also journaled in the side plates 318 and 320 is a clutch and cam shaft364. Mounted on the shaft 364 is an electric clutch 366 and a cam 3&8.The left-hand portion of the shaft 364 is secured to one clutch plate ofthe clutch 366 and is journaled in plate 318 by bearing 37%. The bearing370 is retained in the plate 318 by bearing retaining cap 372 and aninner retaining ring 374 fastened together by screws 376. The right-handportion of shaft 364 is secured to the other clutch plate of clutch 366and is journaled in bearing 378 in side plate 320. A gear 380 is securedto the end of shaft 364 by set screw 382 and meshes with gear 384 on theoutput shaft 386 of a speed reducer 338. The speed reducer 388 issecured to the plate 318 and has as its input shaft the output of motorMOT-l. The motor MOT-l drives one end of shaft 354 through the speedreducer 388, gears 384 and 380, up to the clutch 366. Actuation ofclutch 366 drives the cam end of shaft 364 and produces movement of cam368.

As seen in FIGS. 7 and 9, a cam follower 390, formed as an integral partof yoke 392, rides on cam 355 and produces movement of yoke 392 uponrotation of the cam. The yoke 392 extends downward and is pivoted to theplates 318 and 329 by pin 394 so that upon movement of cam 363 the yokerevolves about the pins 394. A too 3% is formed on each end of the yoke392 and is fastened to the bottom of gibs 35% by pins 3% so that, as theyoke 392 is pivoted about the pin 324, the gib 354i is moved upward ordownward with the movement of toe 396. Thus, the pressure roller "72 maybe moved into and out of contact with the heated roller 7t).

When the cam 3&8 has revolved approximately a quarter turn, it is at theposition of maximum movement for yoke 392 and the yoke contacts canlimit switch LS-ll, which cuts off the power to motor MOT-l. The motorMOT-d has a braking action built therein to immediately stop movement ofcam 363. The movement of yoke 392 to move the pressure roller '72 intocontact with roller 79 is against the action of a pair of compressionsprings 462, one of which is shown in FIGS. '7 and 9. The spring MP2 ismounted on an internal guide 464 secured to the yoke 3% beneath the pin3%. The spring 4% acts against a shoulder portion of the guide 404 andagainst a bracket 4% secured to base frame 4%. The action of spring 4-02forces the yoke 3% about pin 3% against cam 36% in such a direction asto tend to separate rollers 72 and 7d. When the power to motor MOT-1 iscut off, the power is maintained on clutch 366 so that the force ofspring 4% does not force the yoke 392 against the cam Edd so that thecam would rotate. The friction of the clutch 3dr in the gears 38d and 385 provents rotation of the cam 36?. The motor MOT-l has a built in brakewhich is actuated when the power is cut off to immediately stop themotor. When the power is cut off, the clutch 366 and the clutch platesdisengage, a small torsion spring 410 rotates cam 368 back to theposition of minimum travel of yoke 322, and yoke 39?; is pivoted aboutpin 394 by the force of compression springs 4%2 so that pressure roller72 is withdrawn from contact with the heated roller 70.

The movement of the pressure roller 82 of the web cleaner 76 iscoordinated with the movement of the pressure roller '72 of the heatfuser. The actuation of the cleaning roller 82 is also controlled bymovement of yoke 392 under the influence of cam 368 so that the pressureroller is only in contact with the Xerographic drum during the timesthat the pressure roller 72 of the fuser is in contact with the heatedroller '70. As previously pointed out, the cleaning roller 82 issupported by a pair of yokes id and 216 pivotally mounted about torquetube 218. Yoke 236 has a slide bar 412 pivotally connected thereto bypivot pin 414. The slide bar 412 has a slot 416 sized to permit movementof the slide bar about a bolt 41%. The bolt 41% passes through the slot416 and is mounted in a dog 42% on the yoke 35 2. At the opposite end ofthe web cleaning yoke 216 is mounted compression spring 236. Aspreviously described, the compresison spring 236 causes the yoke 216 tobe pivoted about the torque tube 218 so that the cleaning roller 32 isforced into contact with the xerographic drum l8. When the main yoke 392is forced by springs 4&2 back to the low point of cam 36%, separatingthe rollers 7d and 72, the web cleaning yoke 216 is drawn about torquetube 218 against the action of spring 236 by means of the bolt 418 inthe dog 52i pulling against the slide bar 412 pivoting the yoke aboutthe torque tube. In the opposite direction, when the main yoke 392 ismoved forward, the bolt 51% tends to move along the slot 4-116permitting the compression spring 236 to pivot the yoke 216 about thetorque tube.

Drive system The drive system for the entire apparatus is located on theright-hand side of the machine and is seen in FIGS. 3 and 6. Main drivemotor MOT-2 is mounted at the bottom of the machine and drives a pulley5il2 through gear box 563. Power is transmitted from the motor MOT2 andthe pulley 5&2 to an idler shaft 508 by means of belt 5% and pulley 5%.The power is further transmitted to the main idler shaft 514 at reducedspeed by means of pulley 51d and belt 512. The belt 512 passes around apair of idler pulleys Site and 5113 and pulley 520 on shaft 514.

All the portions of the machine which are driven from the main drivemotor are driven off the main idler shaft Sit-t. As shown in FIG. 6, thexerographic drum 13 is driven from belt 522; the fuser, which alsoserves as the driving force for paper web 35, is driven from belt 524;the web take-up roll as is driven from belt 526; the pinch rollers 52driving the web intermediate the fuser and the web take-up roll aredriven by belt 528; and the pinch rolls located at the paper cutter 62are driven by belt The Xerographic drum drive belt 522 is driven bypulley 532 and drives pulley 534 mounted on shaft 536. Also mounted onshaft 536 is gear 538 which drives a gear train consisting of gear 54-0,spur gear 542, and the gear 2% mounted on the Xerographic drum shaft248. Thus, when the main drive motor MOT2 is started, power istransmitted directly to the Xerographic drum through the belts SM, 522,and the gear train just described. Also mounted on the shaft 248 is aspur gear 544 which drives gear 250 in the gear train of the webcleaner, as described above. Therefore, it can be seen thatsimultaneously with the movement of the Xerographic drum, movement ofthe web cleaner is effected. For simplicity purposes, the gear train forthe web cleaner has not been shown in FIG. 6 but is shown in detail inFIG. 7. The belt 524 driving the fuser '76 is driven by pulley 5455 anddrives pulley 548. Both the heated roll 7%? and the pressure roll 72 ofthe fuser are driven through a gear train consisting of a gear 55%mounted on the same shaft as the pulley 54-3, an idler gear 552 whichmeshes with the gear 5% and with a gear 554 mounted on the heater rollshaft. The gear 554 also meshes with and drives gear 556 mounted on thepressure roll shaft.

The two pairs of pinch rolls for driving the paper web are both drivenin the same manner; that is, belts 523 and 536 are driven by pulleys 558and 563, respectively, and drive pulleys 562 and 564 on shafts 566 and568, respectively. The shafts 566 and 568 each have a gear 57% .at theopposite end of the shaft which meshes with and drives a gear 572 on theshafts 574. The shafts 574 are the drive shafts for the pinch rollersand have a covering of rubber which is in contact with the idler roll5'76, also covered with rubber.

Finally, the paper web take-up roll as mounted on V shaft 578 is drivenby belt 526 from pulley 580 on shaft 514 to pulley 582 on shaft 573. Thepulleys and gears are properly sized so that the'web 36 is driven atconstant speed through the fuser 'Ttl and through either pair of pinchrolls onto take-.ip roll 60. Likewise, the peripheral speed of drum 1%is the same as the peripheral speed of the fuser 76 so that when the web36 is electrostatically tacked to the Xerograpnic drum surface bytransfer corotron 63, the surface of the drum is traveling at the samespeed as the surface of the web and there is no relative motion betweenthe two surfaces.

Paper cutter Referring now to FTGS. 12 through 14-, there is shown papercutter 62. The cutter is supported in two side plates 6532 and oddmounted on a cross-member 6%. A cutter roll 6% extends between the twoside plates 662 and and is journaled therein. The cutter roll extendsacross the width of the paper web 2 6 and has, mounted in a groovetherein, a rotary cutter blade 6110 held in place by means of set screws612.

immediately above the cutter roll sea is a stationary cutter blade 6Mmounted in an adjustable mounting block 616 by means of a series ofscrews 618. Thead-

1. IN A XEROGRAPHIC REPRODUCING APPARATUS HAVING A ROTATABLE XEROGRAPHICDRUM ON WHICH XEROGRAPHIC POWDER IMAGES MAY BE FORMED, MEANS FORTRANSFERRING XEROGRAPHIC POWDER IMAGES FORM THE DRUM SURFACE TO ASUPPORT SURFACE, DRUM CLEANING APPARATUS FOR APPLYING CLEANING MATERIALTO THE DRUM SURFACE FOR REMOVING RESIDUAL POWDER IMAGES FORM THE DRUMSURFACE AFTER TRANSFER, MEANS FOR FUSING TRANSFERRED XEROGRAPHIC POWDERIMAGES TO THE SUPPORT SURFACE, THE COMBINATION OF A MOVABLE MEMBER INTHE CLEANING APPARATUS MOVABLE TO AN OPERATIVE POSITION IN WHICH ITPRESSES A CLEANING MATERIAL INTO SURFACE CONTACT WITH THE XEROGRAPHICDRUM AND TO AN INOPERATIVE POSITION IN WHICH THE CLEANING MATERIAL ISREMOVED FROM THE DRUM SURFACE, A MOVABLE MEMBER IN THE FUSING APPARATUSMOVABLE TO AN OPERATIVE POSITION IN WHICH IT IS EFFECTIVE TO